The long term goal is to develop a safe and effective vaccine for gonorrhae. First, our aim is to develop an in vivo model system for gonorrhae. The eye of the rabbit, particularly after some form of traumatization, is reported to be susceptible to infection and is our proposed model system. Second, is to characterize the immune response to the pilar common antigenic determinant. In this part of the study the production of different class immunoglobins will be achieved, reasoning that the production of secretory immunoglobins should be most protective mechanism. Third, will be to determine the protective effect of the pilar common antigen against virulent N. gonorrhaeae with different serotypes of pili. This will be carried out after the development of the in vivo animal model. Next, the common antigenic structures of N. gonorrhaeae will be analyzed and in the case of the pilar common antigenic sites the particular amino acid sequence will be investigated for protective activity. This project would be a prelude to actual testing of a pili subunit vaccine in humans.